I will get some measurements for you. As for stability, I've never really noticed a difference. Both produce a trailer that is equally usable and good handling. The A-frame will have more tongue weight all things equal otherwise. I like the box frame tongue jack arangement better. My one A-frame has the hitch integrated tongue jack, which works well be can't be swung out of the way, and takes a while to crank up. My other one had it on one side, which was problem at times. I also find the box frame easier to hitch up at an angle then the A-frames are.
and has a mason dump body in it. The frame (from the bend to the center of the ball) is 42" , The bent section of the frame is 25" long. It is then attached to the tubing for the surge hitch